Over the recent years, a mobile communication technology has been diversified such as WiMAX (Worldwide Interoperability for Microwave Access) and S3G (Super 3rd Generation) and has been greatly developed by scheming a speedup with HSDPA (High Speed Downlink Packet Access) etc and advancing development of a communication network like NGN (Next Generation Network). Besides, the mobile communication terminal has an increased memory capacity and an increased throughput and also has an improvement of standby time. Moreover, there is a rapid spread in utilizing wireless communications in data communications performed by mobile information terminals such as PDA (Personal Digital Assistants).
With the development of the mobile communication technology such as this, it is considered that applications of the mobile communications will be evolved into an exchange of contents and distribution of the contents between users and further into a variety of services from a simple voice call and an exchange of mails. For example, the Internet etc provides a file exchange, a service for providing user contents advocated in Web2.0 (which is a service for exchanging and changing the user's own contents between the users) and a service for exchanging information by sharing the contents (games etc) in real time between the plurality of users as in the case of an online game, and it is considered that these services will be utilized on the mobile phones.
In particular, if mobility of the mobile phone is utilized, it is feasible to provide a service in which the same information is shared simultaneously between the plurality of users existing in different places, and the users further share feelings etc obtained from the same information with each other. For example, this is a service in which a moving picture captured by one user is distributed in real time to a plurality of friends existing in different places. In this service, the plurality of friends views the same moving picture all together, speaks of their impressions with each other corresponding to details of the picture and conducts operations such as temporarily stopping and rewinding the moving picture at desired timings (e.g.: distribution of moving picture+voice communications+PKT communications).
Note that the following documents are disclosed as the documents of the conventional arts related to the invention of the present application.    [Patent document 1] Japanese Patent Laid-Open Publication No. H11-145992    [Non-Patent document 1] Technical Specification Group Radio Access Network, “Introduction of the Multimedia Broadcast Multicast Service (MBMS) in the Radio Access Network (RAN) Stage 2 (Release 7)”, 3rd Generation Partnership Project, 3GPP TS 25.346 V7.3.0, March 2007